Adds ripple animation to extension buttons on a toolbar

ui/views/controls/button/menu_button.h

Index: ui/views/controls/button/menu_button.h
diff --git a/ui/views/controls/button/menu_button.h b/ui/views/controls/button/menu_button.h
index 1881fd2412ceecf9a8c0a958a3e9e7cd8edf2029..3b87753979a28f50e2067f9631f504985d2a3efe 100644
--- a/ui/views/controls/button/menu_button.h
+++ b/ui/views/controls/button/menu_button.h
@@ -64,6 +64,9 @@ class VIEWS_EXPORT MenuButton : public LabelButton {
   // Activate the button (called when the button is pressed).
   bool Activate();
 
+  // Called to signal that the action will not be activated.
+  void WillNotActivate();

[sadrul, 2015/11/18 22:56:31]

This is .. confusing. The way it is done now, it only means that the button will
not be activated in the next mouse-release. But a subsequent click can still
activate the button, right?

[varkha, 2015/11/18 23:27:54]

This is inlined in OnMouseReleased (see
https://codereview.chromium.org/1411833006/).

+
   // Overridden from View:
   gfx::Size GetPreferredSize() const override;
   const char* GetClassName() const override;